Vehicle-body structure having a center frame that is higher than a floor panel

ABSTRACT

A vehicle-body structure includes a floor panel constituting a floor of an occupant space, a center frame disposed to be higher than and away from the floor panel at a vehicle-width-direction central portion of the occupant space and extending in a front-rear direction, a cross member extending and intersecting the center frame in a plan view in the occupant space, and a connecting member extending upward from the cross member, having an upper portion fixed to the center frame, and connecting the center frame to the cross member.

CROSS-REFERENCES TO RELATED APPLICATIONS

The present application is a continuation application of U.S. Serial No.17/938,966, filed on Sep. 7, 2022, which claims priority to ProvisionalSerial No. 63/403,872 filed on Sep. 6, 2022, Japanese Patent Application2021-183238, filed Nov. 10, 2021, Japanese Patent Application2021-183245, filed Nov. 10, 2021, Japanese Patent Application2021-183251, filed Nov. 10, 2021, Japanese Patent Application2021-183312, filed Nov. 10, 2021, Japanese Patent Application2021-183323, filed Nov. 10, 2021, and Japanese Patent Application2021-161834, filed Sep. 30, 2021, the entire contents of each of whichare incorporated herein by reference.

BACKGROUND Field

The present disclosure relates to a vehicle-body structure of anautomobile.

Description of the Related Art

A tunnel portion extending in a vehicle front-rear direction is formedat a vehicle right-left direction central portion of a floor panel of aconventional automobile. The tunnel portion is a part in which anexhaust pipe extending from an engine room on a vehicle front side to arear portion, a propeller shaft that transfers power of an engine on thevehicle front side to rear wheels, and the like are housed, and thuslargely bulges to a position higher than a bottom portion of a seatcushion.

For example, as disclosed in Patent Literature 1, left-side andright-side tunnel frames extending in the vehicle front-rear directionare provided on right and left sides, respectively, of an upper surfaceportion of the tunnel portion. Each tunnel frame has a cross-sectionopened downward, and flange portions are formed on right and left sides,respectively, of the tunnel frame. The flange portions are joined to theupper surface portion of the tunnel portion such that a closedcross-section structure extending in the vehicle front-rear direction isconstituted by the tunnel portion and the tunnel frames.

CITATION LIST Patent Literature

[Patent Literature 1] Japanese Patent Laid-Open No. 2009-101815

SUMMARY

In an automobile including the tunnel portion as disclosed in PatentLiterature 1, the stiffness of a vehicle body can be improved by thetunnel portion, and the stiffness of the vehicle body can be alsoimproved by the closed cross-section structure constituted by the tunnelportion and the tunnel frames and extending in the vehicle front-reardirection, but it has been a problem how to improve the stiffness of thevehicle body in an automobile including no tunnel portion.

Specifically, a typical tunnel portion largely bulges to a positionhigher than the bottom portion of the seat cushion as described above,and thus the stiffness of the vehicle body can be improved to someextent only by providing such a tunnel portion, but in an automobilewithout the tunnel portion, the stiffness of the vehicle body tends todecrease, and furthermore, it is disadvantage in terms of the stiffnessthat the tunnel frames of Patent Literature 1 cannot be provided.

Thus, such a method is thought that reinforces the floor panel itself byjoining reinforcement members such as the tunnel frames of PatentLiterature 1 to upper and lower surface portions of the floor panel toconstitute a partial closed cross-section structure at the floor panel.However, since the floor panel is positioned at a lower portion of thevehicle body, it is insufficient to only improve the stiffness of thefloor panel, in particular, in order to increase the distortionstiffness of the vehicle body on the whole. If the distortion stiffnessof the vehicle body is increased only with a reinforcement structure ofthe floor panel, a significantly large-scale reinforcement structureneeds to be constituted by the reinforcement members, which leads toweight increase and poor efficiency. Thus, when the distortion stiffnessof the vehicle body needs to be equivalent to or larger than that inPatent Literature 1, a reinforcement structure as in Patent Literature 1is needed at a part higher than and away from the floor panel, but sucha reinforcement structure cannot be employed for the floor panel of afloor tunnel-less structure including no tunnel portion as describedabove.

In an assumed collision in which an impact load is applied from thefront side of an automobile, deformation of the vehicle cabin uponreception of the impact load needs to be suppressed as much as possible,but since the floor panel of the floor tunnel-less structure includes notunnel frame extending in the vehicle front-rear direction, it ispotentially difficult to suppress deformation of the vehicle cabin.

The present disclosure has been made in view of the above-describedproblem and has an objective to sufficiently improve the distortionstiffness of a vehicle body and suppress deformation of a vehicle cabindue to an impact load from a front side in a vehicle-body structureincluding no floor tunnel largely bulging upward from a floor panel.

Means for Solving the Problems

To achieve the above-described objective, a vehicle-body structureprovided in an automobile may be premised in a first aspect of thepresent disclosure. The vehicle-body structure includes a floor panelconstituting a floor of an occupant space including a seat on which apassenger sits, a center frame disposed to be higher than and away fromthe floor panel at a vehicle-width-direction central portion of theoccupant space and extending in a vehicle front-rear direction, a crossmember extending in a vehicle width direction and intersecting thecenter frame in a plan view in the occupant space, and a connectingmember extending upward from the cross member, having an upper portionfixed to the center frame, and connecting the center frame to the crossmember.

With this configuration, since the cross member is provided in theoccupant space, a vehicle-body reinforcement effect by the cross memberis obtained. Moreover, since the center frame higher than and away fromthe floor panel is connected to the cross member through the connectingmember, the distortion stiffness of the vehicle body can be sufficientlyimproved although the floor panel has a floor tunnel-less structure.

In addition, since the connecting member is fixed to the cross member,the fixation strength of the connecting member can be increased.Accordingly, inclination of the connecting member in the front-reardirection is suppressed when an impact load from the front side isapplied, and thus a vehicle-cabin deformation suppression effect by thecenter frame can be sufficiently obtained.

The cross member according to a second aspect of the present disclosurehas an opened sectional structure that is opened downward and is fixedto an upper surface of the floor panel, and a closed cross-section isconstituted by the cross member and the floor panel.

With this configuration, since the stiffness of the cross memberincreases, connection strength by the connecting member can be furtherincreased.

The connecting member according to a third aspect of the presentdisclosure includes a first connecting member and a second connectingmember separately disposed on a vehicle rear side from the firstconnecting member. The cross member includes a first cross member and asecond cross member separately disposed on the vehicle rear side fromthe first cross member. A lower portion of the first connecting memberis fixed to the first cross member, and a lower portion of the secondconnecting member is fixed to the second cross member.

With this configuration, since the center frame can be connected to thefirst cross member and the second cross member disposed at an intervalfrom each other in the vehicle front-rear direction, the connectionstrength of the center frame can be further increased.

The vehicle-body structure according to a fourth aspect of the presentdisclosure further includes a seat rail supporting the seat. The seatrail is attached to at least one of the first cross member and thesecond cross member.

Accordingly, since the cross member is a member to which the seat railis attached, the stiffness of the cross member increases and theconnection strength by the connecting member can be further increased.

The seat rail according to a fifth aspect of the present disclosureextends from the first cross member to the second cross member, a frontportion of the seat rail is attached to the first cross member, and arear portion of the seat rail is attached to the second cross member.

With this configuration, since the first cross member and the secondcross member are connected through the seat rail, the stiffness of thefirst cross member and the second cross member increases. Accordingly,the connection strength by the connecting member can be furtherincreased.

The seat rail according to a sixth aspect of the present disclosureincludes a left-side seat rail supporting a left-side seat and aright-side seat rail supporting a right-side seat. The cross memberincludes a common bracket to which the left-side seat rail and theright-side seat rail are attached in a state in which the left-side seatrail and the right-side seat rail are separated from each other in thevehicle width direction. A lower portion of the connecting member isfixed to the common bracket between the left-side seat rail and theright-side seat rail.

With this configuration, since the common bracket to which the left-sideseat rail and the right-side seat rail are attached is a member having ahigh strength and has a sufficiently long dimension in the vehicle widthdirection, a largest range of fixation to the cross member body isobtained and the fixation strength increases. Since the lower portion ofthe connecting member is fixed to the common bracket having a highstrength and a high fixation strength in this manner, the connectionstrength by the connecting member can be further increased.

Advantages

As described above, since a center frame higher than and away from afloor panel and extending in a vehicle front-rear direction is connectedto a cross member extending in a vehicle width direction through aconnecting member, it is possible to improve the distortion stiffness ofa vehicle body and suppress deformation of a vehicle cabin due to animpact load from the front side in a vehicle-body structure including afloor panel of a floor tunnel-less structure including no floor tunnellargely bulging upward from the floor panel.

BRIEF DESCRIPTION OF THE DRAWINGS

The scope of the present disclosure is best understood from thefollowing detailed description of exemplary embodiments when read inconjunction with the accompanying drawings.

FIG. 1 is a side view of an automobile having a vehicle-body structureaccording to an embodiment of the present disclosure.

FIG. 2 is a perspective view illustrating a state in which theautomobile is divided into an upper-portion structural body and alower-portion structural body.

FIG. 3 is a perspective view in which part of the vehicle-body structureis viewed from an upper side.

FIG. 4 is a plan view of part of the vehicle-body structure.

FIG. 5 is a cross-sectional diagram along line V-V in FIG. 4 .

FIG. 6 is a cross-sectional diagram along line VI-VI in FIG. 4 .

FIG. 7 is a cross-sectional diagram along line VII-VII in FIG. 4 .

FIG. 8 is a perspective view illustrating an occupant-space-side floorpanel and the vicinity thereof in an enlarged manner.

FIG. 9 is a cross-sectional diagram illustrating a seat rail and thevicinity thereof in an enlarged manner.

FIG. 10 is a plan view illustrating part of the seat rail and thevicinity thereof in an enlarged manner.

FIG. 11 is a perspective view illustrating a mounting part of the seatrail and the vicinity thereof in an enlarged manner.

FIG. 12 is a cross-sectional diagram of a bend portion of a center frameand the vicinity thereof.

FIG. 13 is a cross-sectional diagram of the vicinity of a front portionof a rear-side frame member constituting the center frame.

FIG. 14 is a perspective view of a connection member.

FIG. 15 is a perspective view of the connection member when viewed inanother direction.

FIG. 16 is a side view of the connection member.

FIG. 17 is a cross-sectional diagram of an air-conditioning device andthe vicinity thereof.

FIG. 18 is a perspective view illustrating a rear-portion vehicle-bodystructure in a case in which the tilt angle of the center frame isincreased.

FIG. 19 is a cross-sectional diagram illustrating the case in which thetilt angle of the center frame is increased.

FIG. 20 is a perspective view of a dash panel and the vicinity thereofwhen viewed from a vehicle rear side.

FIG. 21 is a schematic diagram of a cooling path.

FIG. 22 is a diagram of a layout of a supply pipe and a discharge pipefor cooling water when viewed from the rear side.

FIG. 23 is a diagram of the layout of the supply pipe and the dischargepipe for the cooling water when viewed from a left side.

DETAILED DESCRIPTION

Non-limiting embodiments of the present disclosure will be describedbelow in detail with reference to the accompanying drawings. Thefollowing description of the preferable embodiments is merely exemplaryin essence and not intended to limit the present disclosure, itsapplication, nor its usage.

FIG. 1 is a side view of an automobile 1 including a vehicle-bodystructure A according to a non-limiting embodiment of the presentdisclosure when viewed from left. In description of the non-limitingembodiment, a vehicle front-rear direction is simply referred to as a“front-rear direction”, a vehicle front side is simply referred to as a“front side”, and a vehicle “rear side” is simply referred to as a “rearside”. In addition, a vehicle width direction is the right-leftdirection of the vehicle, a vehicle left side is simply referred to as a“left side”, and a vehicle right side is simply referred to as a “rightside”.

Entire Structure of Automobile

The automobile 1 is a passenger automobile, and an occupant space R1 inwhich a passenger boards is provided at a front-rear directionintermediate portion of the automobile 1. The occupant space R1 includesfront seats (front-row seats) FS included in a front row, and rear seats(rear-row seats) RS included in a rear row. The front seats FS include adriver seat arranged on the right side (or the left side) in theoccupant space R1, and a front passenger seat arranged on the left side(or the right side) in the occupant space R1. The rear seats RS arearranged on the right and left sides, respectively, in the occupantspace R1. Third-row seats may be arranged on the rear side of the rearseats RS. The rear seats RS are not essential and may be omitted.

A front door FD and a rear door RD are disposed on each of the left andright sides of the occupant space R1. The rear door RD may be omitted ina case of the automobile 1 including no rear seats RS.

A front-side space R2 is provided on the front side of the occupantspace R1 in the automobile 1. A powertrain PT can be mounted in thefront-side space R2 as necessary. When the powertrain PT is mounted inthe front-side space R2, the front-side space R2 may be called, forexample, a powertrain storage room, a motor room, or an engine room. Abonnet hood BF is provided at an upper portion of the front-side spaceR2.

A trunk space R3 in which a package or the like can be housed isprovided on the rear side of the occupant space R1 in the automobile 1.The trunk space R3 can be opened and closed by a trunk lid TR. Arear-side space R4 is provided on the rear side of the occupant space R1and at a lower position than the trunk space R3 in the automobile 1. Thepowertrain PT that generates power for the automobile 1 can be mountedin the rear-side space R4 as necessary. When the powertrain PT ismounted in the rear-side space R4, the rear-side space R4 may be called,for example, a powertrain storage room, a motor room, or an engine room.

The powertrain PT may be mounted in each of the front-side space R2 andthe rear-side space R4 or the powertrain PT may be mounted in one ofthem. A front-wheel-drive vehicle in which only front wheels FT aredriven by the powertrain PT is achieved when the powertrain PT ismounted only in the front-side space R2, or a rear-wheel-drive vehiclein which only rear wheels RT are driven by the powertrain PT is achievedwhen the powertrain PT is mounted only in the rear-side space R4.Alternatively, a four-wheel-drive vehicle is achieved when the frontwheels FT and the rear wheels RT are driven by the powertrains PTmounted in both the front-side space R2 and the rear-side space R4.

Each powertrain PT includes at least a traveling motor M (illustrated inFIG. 2 ) for driving a drive wheel and also includes a speed reducer, atransmission, or the like as necessary. Thus, the automobile 1 is anelectric vehicle. The traveling motor M is disposed such that therotation center thereof extends in the right-left direction. Thepowertrain PT may include, for example, a controller in addition to thetraveling motor M. The powertrain PT may include an internal combustionengine. A battery unit Y (also illustrated in FIG. 1 ) for supplyingelectric power to the traveling motor M is mounted at a lower portion ofthe automobile 1. For example, the battery unit Y may be charged byusing power generated by the internal combustion engine, and either thefront wheels FT or the rear wheels RT or both may be driven by powergenerated by the internal combustion engine.

The type of the automobile 1 does not necessarily need to be a four-doorvehicle as exemplarily illustrated in FIG. 1 and may be, for example, anautomobile including no rear doors RD. The present disclosure is alsoapplicable to an automobile, such as a hatchback vehicle, in which therear-side space R4 can be opened and closed by a tail gate.

As illustrated in FIG. 2 , the automobile 1 includes a lower-portionstructural body 2 and an upper-portion structural body 3, and thevehicle-body structure A is constituted by the lower-portion structuralbody 2 and the upper-portion structural body 3. FIG. 2 illustrates astate in which the doors FD and RD, the bonnet hood BF, a fender, windowglasses, a roof, a center pillar, a rear pillar, a bumper, front andrear lighting devices, an instrument panel, the front and rear seats,and the like, which are included in the upper-portion structural body 3in reality, are removed. FIG. 2 also illustrates a state in which thefront wheels FT, the rear wheels RT, a suspension device, and the like,which are included in the lower-portion structural body 2 in reality,are removed.

The lower-portion structural body 2 includes the battery unit Y. Thebattery unit Y includes a front-side battery FB, a rear-side battery RB,and a rack frame 10 surrounding the front-side battery FB and therear-side battery RB. The lower-portion structural body 2 also includesa front support frame 20 extending from a front portion of the rackframe 10 toward the front side, and a rear support frame 30 extendingfrom a rear portion of the rack frame 10 toward the rear side.

In a typical electric automobile, a battery unit is often detachablyattached as a separated body from a vehicle body under a floor, but inthe present embodiment, not only the batteries FB and RB but also thefront support frame 20 and the rear support frame 30 are integrated withthe rack frame 10 surrounding the batteries FB and RB, and the frontsupport frame 20 and the rear support frame 30 are detachably attachedto the upper-portion structural body 3 together with the batteries FBand RB.

Specifically, the automobile 1 of the present embodiment is configuredto be able to be divided in the up-down direction into the lower-portionstructural body 2 including the batteries FB and RB, and theupper-portion structural body 3 in which the occupant space R1 and thetrunk space R3 are formed. Being able to be divided in the up-downdirection means integration of the lower-portion structural body 2 withthe upper-portion structural body 3 by using fastening members such asbolts and nuts, screws, and the like without using welding, bonding, andthe like. Accordingly, the lower-portion structural body 2 can beseparated from the upper-portion structural body 3 as necessary whenmaintenance and repair are performed after the automobile 1 is handedover to a user, and thus maintainability is excellent.

A vehicle-body structure of a ladder frame type is known as thevehicle-body structure of an automobile. In a case of the vehicle-bodystructure of the ladder frame type, division into a ladder frame and acabin in the up-down direction is possible, but the ladder framecontinuously extends in the front-rear direction and thus mainlyreceives a collision load at front collision and rear collision. At sidecollision, the ladder frame only supplementarily receives a collisionload, and the collision load is mainly received by the cabin. In thismanner, in the vehicle-body structure of the ladder frame type, it isnormal that a member that receives a collision load is different betweenfront or rear collision and side collision.

However, in a case of the automobile 1 of the present embodiment, thelower-portion structural body 2, which includes the front support frame20 and the rear support frame 30, and the upper-portion structural body3 can be divided from each other, but its technical idea is largelydifferent from that of the conventional vehicle-body structure of theladder frame type in that a collision load is received by thelower-portion structural body 2 and the upper-portion structural body 3in both cases of front or rear collision and side collision and thus thecollision load can be dispersed to and absorbed by the structural bodies2 and 3. Hereinafter, the structures of the lower-portion structuralbody 2 and the upper-portion structural body 3 will be sequentiallydescribed.

Lower-Portion Structural Body

First, the lower-portion structural body 2 will be described below. Thelower-portion structural body 2 includes the powertrain PT, the frontwheels FT, the rear wheels RT, and front-side suspension devices SP1 andSP2 and rear-side suspension devices SP3 and SP4, which are illustratedwith virtual lines in FIG. 4 , in addition to the batteries FB and RB,the rack frame 10, the front support frame 20, and the rear supportframe 30. The formats of the front-side suspension devices SP1 and SP2and the rear-side suspension devices SP3 and SP4 are not particularlylimited, and the vehicle-body structure may be changed in accordancewith the formats of the front-side suspension devices SP1 and SP2 andthe rear-side suspension devices SP3 and SP4.

As illustrated in FIG. 2 , the rack frame 10 as a framework of thebattery unit Y is a member for surrounding and protecting the front-sidebattery FB, the rear-side battery RB, harnesses, and the like. The rackframe 10 is formed in such a large size that, on the lower side of anoccupant-space-side floor panel 41 to be described later, the rack frame10 extends from the vicinity of a left end portion of theoccupant-space-side floor panel 41 to the vicinity of a right endportion thereof and extends from the vicinity of a front end portion ofthe occupant-space-side floor panel 41 to the vicinity of a rear endportion thereof. In this manner, since the rack frame 10 is provided ina large part of a region on the lower side of the occupant-space-sidefloor panel 41, the batteries FB and RB having large capacities can bemounted on the automobile 1. The batteries FB and RB may be, forexample, lithium-ion batteries or all-solid-state batteries or may beany other secondary batteries. Alternatively, the batteries FB and RBmay be what is called battery cells or may be battery packs in which aplurality of battery cells are housed.

The rack frame 10 includes a left side member 11, a right side member12, a front-side member 13, and a rear-side member 14. The left sidemember 11, the right side member 12, the front-side member 13, and therear-side member 14 are formed of, for example, an extruded materialmade of an aluminum alloy, but may be formed of a press-formed materialsuch as an aluminum alloy plate material or a steel plate. Indescription below, an “extruded material” is an extruded material madeof an aluminum alloy, and a “press-formed material” is a press-formedmaterial such as an aluminum alloy plate material or a steel plate.Alternatively, each member may be formed of, for example, cast metal ordie cast.

A cross-sectional shape of each of the left side member 11, the rightside member 12, the front-side member 13, and the rear-side member 14 ina direction orthogonal to its longitudinal direction is a rectangularshape. The left side member 11, the right side member 12, the front-sidemember 13, and the rear-side member 14 are all arranged at the sameheight and substantially horizontally extend. When the lower-portionstructural body 2 is to be connected to the upper-portion structuralbody 3, the front-side member 13 is fastened and fixed to a lowerportion of a dash panel 50 by a fastening member, and the left sidemember 11 and the right side member 12 are fastened and fixed to rightand left side sills 60, respectively, by fastening members. Therear-side member 14 is fastened and fixed to a connection panel 43,which will be described later, by a fastening member.

The left side member 11 is provided at a left end portion of thelower-portion structural body 2 and extends in the front-rear direction.The right side member 12 is provided at a right end portion of thelower-portion structural body 2 and extends in the front-rear direction.The left side member 11 and the right side member 12 are arranged on avehicle-width-direction inner side of the right and left side sills 60,respectively, to be described later. The front-side member 13 isprovided at a front portion of the battery unit Y and extends in theright-left direction from a front end portion of the left side member 11to a front end portion of the right side member 12. A left end portionof the front-side member 13 and the front end portion of the left sidemember 11 are connected to each other, and a right end portion of thefront-side member 13 and the front end portion of the right side member12 are connected to each other. The rear-side member 14 is provided at arear portion of the battery unit Y and extends in the right-leftdirection from a rear end portion of the left side member 11 to a rearend portion of the right side member 12. A left end portion of therear-side member 14 and the rear end portion of the left side member 11are connected to each other, and a right end portion of the rear-sidemember 14 and the rear end portion of the right side member 12 areconnected to each other.

A cover member 15 as a bottom plate is attached to a lower portion ofthe rack frame 10. The rack frame 10 is blocked from the lower side bythe cover member 15. The cover member 15 substantially horizontallyextends and is fixed to lower surfaces of the left side member 11, theright side member 12, the front-side member 13, and the rear-side member14 and also fixed to the side sills 60 as described later. Note that anupper portion of the rack frame 10 may be blocked by a lid or may beblocked by the occupant-space-side floor panel 41 to be described later.Note that electric power of the batteries FB and RB housed in the rackframe 10 is supplied to the traveling motor M through a travelingcontrol circuit. The batteries FB and RB can be charged through acharging socket.

FIG. 5 illustrates a cross-section of a right-left direction centralportion of the vehicle-body structure A. As illustrated in FIG. 5 ,first to third battery-side cross members (cross structures) 10A, 10B,and 10C as reinforcement members extending in the right-left directionare provided inside the rack frame 10. The heights of the first to thirdbattery-side cross members 10A, 10B, and 10C are all the same and arethe same as the heights of the front-side member 13 and the rear-sidemember 14. The first to third battery-side cross members 10A, 10B, and10C may be formed of extruded materials or may be formed of press-formedmaterials. In the present embodiment, the three battery-side crossmembers 10A, 10B, and 10C are provided, but the number of thebattery-side cross members 10A, 10B, and 10C may be increased ordecreased in accordance with dimensions of the rack frame 10 in thefront-rear direction.

The first to third battery-side cross members 10A, 10B, and 10C arearranged at an interval from each other in the front-rear direction, thefirst battery-side cross member 10A is positioned farthest on the frontside, and the third battery-side cross member 10C is positioned fartheston the rear side. Lower portions of the battery-side cross members 10A,10B, and 10C are fixed to an upper surface of the cover member 15. Leftend portions of the battery-side cross members 10A, 10B, and 10C arefixed to an inner surface (right-side surface) of the left side member11, and right end portions of the battery-side cross members 10A, 10B,and 10C are fixed to an inner surface (left-side surface) of the rightside member 12. In other words, the battery-side cross members 10A, 10B,and 10C are members connecting the left side member 11 and the rightside member 12.

A front-portion central member 16 and first to third rear-portioncentral members 17 to 19 as reinforcement members extending in thefront-rear direction are provided inside the rack frame 10. Thefront-portion central member 16 and the first to third rear-portioncentral members 17 to 19 may be referred to as a battery frame extendingin the front-rear direction, and the battery unit Y has a structureincluding the battery frame constituted by the front-portion centralmember 16, the first to third rear-portion central members 17 to 19, andthe like. The left side member 11, the right side member 12, thefront-side member 13, and the rear-side member 14 may be included in thebattery frame.

The front-portion central member 16 and the first to third rear-portioncentral members 17 to 19 are arranged at substantially same heights andprovided at a right-left direction center of the rack frame 10. Lowerend portions of the front-portion central member 16 and the first tothird rear-portion central members 17 to 19 are attached to the uppersurface of the cover member 15. The front-portion central member 16 andthe first to third rear-portion central members 17 to 19 extend from thefront-side member 13 to the rear-side member 14.

The front-portion central member 16 is arranged between the front-sidemember 13 and the first battery-side cross member 10A, a front endportion of the front-portion central member 16 is fixed to a right-leftdirection central portion of the front-side member 13, and a rear endportion of the front-portion central member 16 is fixed to a right-leftdirection central portion of the first battery-side cross member 10A.Accordingly, the front-side member 13 is a member extending to connectthe front end portions of the left side member 11 and the right sidemember 12 to the front end portion of the front-portion central member16.

The first rear-portion central member 17 is arranged between the firstbattery-side cross member 10A and the second battery-side cross member10B, a front end portion of the first rear-portion central member 17 isfixed to the right-left direction central portion of the firstbattery-side cross member 10A, and a rear end portion of the firstrear-portion central member 17 is fixed to a right-left directioncentral portion of the second battery-side cross member 10B. The secondrear-portion central member 18 is arranged between the secondbattery-side cross member 10B and the third battery-side cross member10C, a front end portion of the second rear-portion central member 18 isfixed to the right-left direction central portion of the secondbattery-side cross member 10B, and a rear end portion of the secondrear-portion central member 18 is fixed to a right-left directioncentral portion of the third battery-side cross member 10C. The thirdrear-portion central member 19 is arranged between the thirdbattery-side cross member 10C and the rear-side member 14, a front endportion of the third rear-portion central member 19 is fixed to theright-left direction central portion of the third battery-side crossmember 10C, and a rear end portion of the third rear-portion centralmember 19 is fixed to a right-left direction central portion of therear-side member 14. Accordingly, the first to third battery-side crossmembers 10A, 10B, and 10C and the front-portion central member 16 andthe first to third rear-portion central members 17 to 19 are disposed ina lattice shape and connected to each other inside the rack frame 10,which further increases the effect of reinforcing the rack frame 10 andthus the effect of reinforcing the lower-portion structural body 2.

When a virtual straight line extending in the front-rear direction in aplan view is assumed, the positions of the front-portion central member16 and the first to third rear-portion central members 17 to 19 in theright-left direction are set such that the members are arranged on thevirtual line. In other words, the members are provided such that thefirst to third rear-portion central members 17 to 19 are positioned on avirtual extended line from the front-portion central member 16 on therear side. Note that the front-portion central member 16 and the firstto third rear-portion central members 17 to 19 may be formed as onemember that is continuous in the front-rear direction. In this case, theone member extends from the front-side member 13 to the rear-side member14.

As illustrated in FIG. 2 , a pair of right and left front support frames20 are provided and substantially horizontally extend in straight lineson the lower side of the upper-portion structural body 3. Each frontsupport frame 20 may be formed of, for example, an extruded material ora press-formed material. In the present embodiment, each front supportframe 20 is formed of an extruded material, and thus a cross-sectionalshape thereof in a direction orthogonal to the front-rear direction issubstantially constant from a front end portion to a rear end portion.

The left-side front support frame 20 is connected to a site on the leftside of a right-left direction center of the front-side member 13constituting the front portion of the rack frame 10, and this connectionsite is positioned on the right side of the left side member 11 of therack frame 10. The right-side front support frame 20 is connected to asite on the right side of the right-left direction center of thefront-side member 13, and this connection site is positioned on the leftside of the right side member 12 of the rack frame 10. The heights ofthe right and left front support frames 20 are substantially the same.

The front-side powertrain PT is attached to each front support frame 20through a mounting member. In this case, the front support frame 20serves as a front-side motor support frame that supports the travelingmotor M on the front side of the battery unit Y. In the lower-portionstructural body 2, drive shafts S1 through which output from thepowertrain PT (rotational force of the traveling motor M) is transferredto the right and left front wheels FT, respectively, are provided on theright and left sides.

Right and left suspension arms constituting parts of the front-sidesuspension devices SP1 and SP2 illustrated with virtual lines in FIG. 4are freely swingably supported to the right and left front supportframes 20, respectively, in the up-down direction. The front supportframes 20 may be members for supporting the suspension arms withoutsupporting the powertrain PT.

As illustrated in FIG. 2 , similarly to the front support frames 20, apair of right and left rear support frames 30 are provided andsubstantially horizontally extend in straight lines toward the rearside. Each rear support frame 30 may be formed of, for example, anextruded material or a press-formed material. In the present embodimenteach rear support frame 30 is formed of an extruded material.

The left-side rear support frame 30 is connected to a site on the leftside of a right-left direction center of the rear-side member 14constituting the rear portion of the rack frame 10, and this connectionsite is positioned on the right side of the left side member 11 of therack frame 10. The right-side rear support frame 30 is connected to asite on the right side of the right-left direction center of therear-side member 14, and this connection site is positioned on the leftside of the right side member 12 of the rack frame 10.

The rear-side powertrain PT is attached to each rear support frame 30through a mounting member. In this case, the rear support frame 30serves as a rear-side motor support frame that supports the rear-sidetraveling motor M of the battery unit Y. In the lower-portion structuralbody 2, drive shafts S2 through which output from the powertrain PT(rotational force of the traveling motor M) is transferred to the rightand left rear wheels, respectively, are provided on the right and leftsides.

Right and left suspension arms constituting parts of the rear-sidesuspension devices SP3 and SP4 illustrated with virtual lines in FIG. 4are freely swingably supported to the right and left rear support frames30, respectively, in the up-down direction. The rear support frames 30may be members for supporting the suspension arms without supporting thepowertrain PT.

Upper-Portion Structural Body

Subsequently, the upper-portion structural body 3 will be describedbelow. The upper-portion structural body 3 includes a floor member 40,the dash panel 50, and the pair of right and left side sills 60. Thefloor member 40 is a member arranged at a higher position than the rackframe 10 and the rear support frames 30 of the lower-portion structuralbody 2. The floor member 40 includes the occupant-space-side floor panel(first floor panel) 41 constituting a floor of the occupant space R1including the front seats FS and the rear seats RS (illustrated in FIG.1 ) on which passengers sits, a trunk-space-side floor panel (secondfloor panel) 42 constituting a floor of the trunk space R3, and theconnection panel 43 connecting a rear portion of the occupant-space-sidefloor panel 41 and a front portion of the trunk-space-side floor panel42. A kick-up portion is constituted by the connection panel 43.

The floor member 40 may be formed of, for example, a member shaped bypressing a steel plate or the like. The occupant-space-side floor panel41, the trunk-space-side floor panel 42, and the connection panel 43 maybe integrally formed or may be formed by separately forming componentsand then connecting them. In the present embodiment, description is madewith the three divided portions of the occupant-space-side floor panel41, the trunk-space-side floor panel 42, and the connection panel 43,but the floor member 40 including the panels 41 to 43 may be referred toas a floor panel. Alternatively, only the occupant-space-side floorpanel 41 may be referred to as a floor panel.

The occupant-space-side floor panel 41 extends from a front portion ofthe occupant space R1 to a rear portion thereof and from a left-sideportion of the occupant space R1 to a right-side portion thereof. Theoccupant-space-side floor panel 41 according to the present embodimenthas a floor tunnel-less structure including no tunnel portion.Specifically, a vehicle-width-direction central portion of a floor panelof a conventional automobile is typically provided with a tunnel portionlargely bulging upward and extending in the front-rear direction. Thetunnel portion is a part for allowing, for example, insertion of anexhaust pipe extending toward the rear side from an engine mounted in anengine room at a vehicle front portion and insertion of a propellershaft through which output from the engine mounted in the engine room atthe vehicle front portion is transferred to rear wheels. The diametersof the exhaust pipe and the propeller shaft are often, for example,equal to or larger than 10 cm, and furthermore, a gap of at leastseveral centimeters or larger needs to be provided between each of theexhaust pipe and the propeller shaft and the floor panel to preventinterference of the exhaust pipe or the propeller shaft with the floorpanel. In addition, for example, an insulator is disposed on an innersurface of the tunnel portion in some cases. With these factors, theheight of bulging of the tunnel portion from the floor panel is, forexample, equal to or larger than 15 cm or equal to or larger than 20 cmin some cases, and as for a positional relation with a seat, an upperend of the tunnel portion is higher than a lower end of a seat cushionon a seat rail or an up-down direction central portion of the seatcushion. A structure without such a tunnel portion largely bulgingupward is a tunnel-less structure.

The occupant-space-side floor panel 41 includes no tunnel portion havinga height equal to or larger than 15 cm or equal to or larger than 20 cmfrom an upper surface of the occupant-space-side floor panel 41 asdescribed above, but may include, for example, a bulging portion havinga low height equal to or smaller than 5 cm or equal to or smaller than10 cm from the upper surface of the occupant-space-side floor panel 41.In a case of such a bulging portion having a low height, neither exhaustpipe nor a propeller shaft can be inserted inside the bulging portion,and thus the bulging portion does not function as a tunnel portion.Thus, the occupant-space-side floor panel 41, which includes a bulgingportion having a low height equal to or smaller than 5 cm or equal to orsmaller than 10 cm from the upper surface of the occupant-space-sidefloor panel 41, is a floor panel of a tunnel-less structure. Inaddition, the occupant-space-side floor panel 41 may be provided with,for example, a rib protruding upward and extending in the front-reardirection. The height of such a rib is several centimetersapproximately, and thus the floor panel is of a tunnel-less structureeven when provided with the rib.

In the present embodiment, since each powertrain PT includes thetraveling motor M, no internal combustion engine needs to be mounted inthe front-side space R2 and thus no exhaust pipe needs to be guided tothe vehicle rear side. When a powertrain PT is mounted in the rear-sidespace R4, the rear wheels RT can be driven by the powertrain PT and apropeller shaft can be omitted. Accordingly, the occupant-space-sidefloor panel 41 can have a tunnel-less structure.

As illustrated in FIG. 3 as well, a recessed portion 41 a formed bulgingdownward is formed at a front-rear direction intermediate portion of theoccupant-space-side floor panel 41. The recessed portion 41 a has abottom surface 41 b on which the feet of a rear-seat passenger sittingon a rear seat RS can be placed. The bottom surface 41 b issubstantially horizontally formed. A front-side part of the recessedportion 41 a is formed to be gradually deeper toward the rear side. Therecessed portion 41 a may be continuously formed from a left sideportion of the occupant-space-side floor panel 41 to a right sideportion thereof.

The bottom surface 41 b of the recessed portion 41 a has a heightsubstantially same as that of a lower portion of the corresponding sidesill 60 to be described later, and accordingly, the height of the bottomsurface 41 b is sufficiently low. The positional relation between therecessed portion 41 a and a seat cushion of each rear seat RS in thefront-rear direction is set such that the feet of a rear-seat passengersitting on the rear seat RS are naturally placed on the bottom surface41 b when the feet are held directly downward. The position of a frontportion of the recessed portion 41 a is set such that the feet of arear-seat passenger sitting on the rear seat RS are placed on the bottomsurface 41 b even when the feet are moved obliquely forward. In otherwords, the position of the recessed portion 41 a and the dimensionthereof in the front-rear direction are set such that the feet of arear-seat passenger can be placed on the bottom surface 41 b when thefeet are moved somehow in the front-rear direction. Accordingly, a footspace for a rear-seat passenger can be expanded, which improvescomfortability. The depth of the recessed portion 41 a may be, forexample, 5 cm or larger, or 10 cm or larger.

A floor frame 41 c extending in the front-rear direction is provided ata right-left direction central portion of the recessed portion 41 a. Alower portion of the floor frame 41 c is fixed to the bottom surface 41b of the recessed portion 41 a. A part at which the recessed portion 41a is formed at the occupant-space-side floor panel 41 can be reinforcedsince the floor frame 41 c is provided.

A rear reinforcement member 47 extending in the front-rear direction isprovided on the rear side of the recessed portion 41 a of theoccupant-space-side floor panel 41. The rear reinforcement member 47 isjoined to the upper surface of the occupant-space-side floor panel 41.The rear reinforcement member 47 may be provided as necessary and may beomitted.

The trunk-space-side floor panel 42 is positioned higher than theoccupant-space-side floor panel 41. The rear-side space R4 is positionedlower than the trunk-space-side floor panel 42. In other words, thetrunk-space-side floor panel 42 is arranged to separate the trunk spaceR3 from the rear-side space R4. The dimension of the trunk-space-sidefloor panel 42 in the front-rear direction is set to be shorter than thedimension of the occupant-space-side floor panel 41 in the front-reardirection.

Since the trunk-space-side floor panel 42 is arranged at a higherposition than the occupant-space-side floor panel 41, the connectionpanel 43 extends in the up-down direction. The connection panel 43 maybe vertical or may be tilted such that the connection panel 43 ispositioned farther on the rear side at a position farther on the upperside.

As illustrated in FIG. 7 as well, the dash panel 50 is a member as apartition wall between the front-side space R2 and the occupant space R1and extends upward from a front portion of the occupant-space-side floorpanel 41 and in the right-left direction as well, thereby partitioningthe front portion of the occupant space R1.

As illustrated in FIG. 4 , the right and left side sills 60 are disposedextending in the front-rear direction at right and left end portions,respectively, of the occupant-space-side floor panel 41. The left endportion of the occupant-space-side floor panel 41 is connected to anup-down direction intermediate portion of the left side sill 60, anupper part of the side sill 60 protrudes upward from a connection siteof the occupant-space-side floor panel 41, and a lower part of the sidesill 60 protrudes downward from the connection site of theoccupant-space-side floor panel 41. Since the battery unit Y includingthe batteries FB and RB is disposed at a lower position than theoccupant-space-side floor panel 41, such arrangement is made that thelower part of the side sill 60 overlaps with the batteries FB and RB ina vehicle side view. Similarly, the right side sill 60 is connected tothe right end portion of the occupant-space-side floor panel 41.

As illustrated in FIG. 3 , the upper-portion structural body 3 includesa pair of right and left hinge pillars 70. The right hinge pillar 70extends upward from a front end portion of the right side sill 60. Theleft hinge pillar 70 extends upward from a front end portion of the leftside sill 60. The right and left front doors FD (illustrated in FIG. 1 )are rotatably attached to the right and left hinge pillars 70,respectively. A left edge portion of the dash panel 50 is connected to aright-side surface of the left hinge pillar 70. A right edge portion ofthe dash panel 50 is connected to a left-side surface of the right hingepillar 70. Note that the upper-portion structural body 3 is alsoprovided with a center pillar, a rear pillar, and the like.

A left-side front-wheel suspension support member 51A that supports thesuspension device (front suspension device) SP1 (illustrated withvirtual lines in FIG. 4 ) for the left front wheel FT is provided on theleft side on the front side of the dash panel 50 in the upper-portionstructural body 3. A right-side front-wheel suspension support member51B that supports the suspension device (front suspension device) SP2(illustrated with virtual lines in FIG. 4 ) for the right front wheel FTis provided on the right side on the front side of the dash panel 50 inthe upper-portion structural body 3. The suspension devices SP1 and SP2are not limited to a particular format but include suspension arms thatfreely swingably support the front wheels FT in the up-down direction,shock absorbers, springs, or the like. End portions of the suspensionarms on the vehicle body side, upper end portions of the shockabsorbers, or the like are attached to the front-wheel suspensionsupport members 51A and 51B. The front-wheel suspension support members51A and 51B can be made of, for example, aluminum die cast, but are notlimited thereto and may be made of a combination of steel plates or thelike.

As illustrated in, for example, FIG. 6 , three left-side fixation frames52A for fixing the left-side front-wheel suspension support member 51Aare provided on the left side on the front side of the dash panel 50.The three left-side fixation frames 52A are arranged at an interval fromeach other in the up-down direction, and front portions of the threeleft-side fixation frames 52A are fixed to the front-wheel suspensionsupport member 51A. Rear portions of the left-side fixation frames 52Aarranged uppermost and at an up-down direction intermediate position arefixed to the left-side hinge pillar 70 and the left side of the dashpanel 50. A rear portion of the left-side fixation frame 52A arrangedlowermost is fixed to the left side sill 60.

As partially illustrated in FIG. 3 , three right-side fixation frames52B for fixing the right-side front-wheel suspension support member 51Bare provided on the right side on the front side of the dash panel 50.The three right-side fixation frames 52B are arranged at an intervalfrom each other in the up-down direction, and front portions of thethree right-side fixation frames 52B are fixed to the front-wheelsuspension support member 51B. Rear portions of the right-side fixationframes 52B arranged uppermost and at an up-down direction intermediateposition are fixed to the right-side hinge pillar 70 and the right sideof the dash panel 50. A rear portion of the right-side fixation frame52B arranged lowermost is fixed to the right side sill 60.

As illustrated in FIG. 2 , a left-side crush can 53A extending towardthe front side is fixed to a front portion of the left-side front-wheelsuspension support member 51A. A right-side crush can 53B extendingtoward the front side is fixed to a front portion of the right-sidefront-wheel suspension support member 51B. A bumper reinforcement 140extending in the right-left direction is attached to a front portion ofthe left-side crush can 53A and a front portion of the right-side crushcan 53B.

As illustrated in FIG. 4 , the upper-portion structural body 3 includesa left-side front frame 54A and a right-side front frame 54B.Specifically, the left-side front frame 54A connecting a front portionof a center frame 80 to be described later and the left-side front-wheelsuspension support member 51A, and the right-side front frame 54Bconnecting the front portion of the center frame 80 and the right-sidefront-wheel suspension support member 51B are provided on the front sideof the dash panel 50. The left-side front frame 54A is tilted such thatthe left-side front frame 54A is positioned farther on the left side ata position farther on the front side. The right-side front frame 54B istilted such that the right-side front frame 54B is positioned farther onthe right side at a position farther on the front side. Since the rightand left front-wheel suspension support members 51A and 51B are eachconnected to the front portion of the center frame 80, the stiffness ofthe front-wheel suspension support members 51A and 51B is increased,which improves maneuvering stability of the vehicle. In addition, thestiffness of the vehicle front side including the vicinity of the dashpanel 50 is increased as well.

The upper-portion structural body 3 includes a left-side rear-side frame112A extending in the front-rear direction on the left side on the rearside of the rear portion of the occupant-space-side floor panel 41, anda right-side rear-side frame 112B extending in the front-rear directionon the right side on the rear side of the rear portion of theoccupant-space-side floor panel 41. A front portion of the left-siderear-side frame 112A is connected to a rear portion of the left-sideside sill 60. A front portion of the right-side rear-side frame 112B isconnected to a rear portion of the right-side side sill 60. A front-reardirection intermediate portion of the left-side rear-side frame 112A anda front-rear direction intermediate portion of the right-side rear-sideframe 112B are connected to each other through a trunk-side cross member(connecting member) 105 extending in the right-left direction.

A left-side rear-wheel suspension support member 110A that supports thesuspension device (rear suspension device) SP3 (illustrated with virtuallines in FIG. 4 ) for the left rear wheel RT is provided on the leftside on the rear side of the connection panel 43 in the upper-portionstructural body 3. The rear-wheel suspension support member 110A isfixed to the left-side rear-side frame 112A. A right-side rear-wheelsuspension support member 110B that supports the suspension device (rearsuspension device) SP4 (illustrated with virtual lines in FIG. 4 ) forthe right rear wheel RT is provided on the right side on the rear sideof the connection panel 43 in the upper-portion structural body 3. Therear-wheel suspension support member 110B is fixed to the right-siderear-side frame 112B. The suspension devices SP3 and SP4 are not limitedto a particular format but include suspension arms that freely swingablysupport the rear wheels RT in the up-down direction, shock absorbers,springs, or the like.

An upper portion of the spring or shock absorber included in theleft-side suspension device SP3 is connected to an upper portion of therear-wheel suspension support member 110A. As illustrated in FIG. 3 ,the upper portion of the rear-wheel suspension support member 110A is aleft-side load input portion 110 a to which loads from the springs orthe shock absorbers are input. An upper portion of the spring or shockabsorber included in the right-side suspension device SP4 is connectedto an upper portion of the rear-wheel suspension support member 110B.The upper portion of the rear-wheel suspension support member 110B is aright-side load input portion 110 b to which a load from the spring orthe shock absorber is input. The left-side load input portion 110 a andthe right-side load input portion 110 b are also fixed to the right andleft sides of the trunk-space-side floor panel 42. In addition, theleft-side load input portion 110 a and the right-side load input portion110 b are connected to each other through the trunk-side cross member105. The trunk-side cross member 105 is joined to an upper surface ofthe trunk-space-side floor panel 42, and a closed cross-sectionstructure extending in the vehicle width direction is constituted by thetrunk-space-side floor panel 42 and the trunk-side cross member 105.

As illustrated in FIG. 2 , a rear-portion cross member 44E is providedat a lower position than the left-side load input portion 110 a and theright-side load input portion 110 b. The rear-portion cross member 44Eis joined to the rear portion of the occupant-space-side floor panel 41.

The upper-portion structural body 3 can be partitioned into, forexample, a front-portion vehicle-body structure and a rear-portionvehicle-body structure. As illustrated in FIG. 4 , the rear-portionvehicle-body structure may be the rear side of the occupant-space-sidefloor panel 41 in the upper-portion structural body 3. A left-side rearframe 111A connecting a rear portion of the center frame 80 and theleft-side rear-wheel suspension support member 110A, and a right-siderear frame 111B connecting the rear portion of the center frame 80 andthe right-side rear-wheel suspension support member 110B are provided onthe rear side of the connection panel 43 of the upper-portion structuralbody 3. Since the right and left rear-wheel suspension support members110A and 110B are each connected to the rear portion of the center frame80, the stiffness of the rear-wheel suspension support members 110A and110B is increased, which improves maneuvering stability of the vehicle.In addition, the stiffness of the vehicle rear side including thevicinity of the connection panel 43 is increased as well.

The left-side rear frame 111A and the right-side rear frame 111B arearranged at a lower position than the trunk-space-side floor panel 42.As illustrated in FIG. 6 , a rear portion of the left-side rear frame111A is fixed to the upper portion of the rear-wheel suspension supportmember 110A, in other words, the left-side load input portion 110 a. Theleft-side rear frame 111A is tilted in a side view such that theleft-side rear frame 111A is positioned farther on the lower side at aposition farther on the front side from the upper portion of therear-wheel suspension support member 110A toward the front side, and isalso tilted in a plan view such that the left-side rear frame 111A ispositioned closer to a vehicle width direction central portion at aposition farther on the front side as illustrated in FIG. 4 . A rearportion of the right-side rear frame 111B is fixed to the upper portionof the rear-wheel suspension support member 110B, in other words, theright-side load input portion 110 b. The right-side rear frame 111B istilted in a side view such that the right-side rear frame 111B ispositioned farther on the lower side at a position farther on the frontside from the upper portion of the rear-wheel suspension support member110B toward the front side, and is also tilted in a plan view such thatthe right-side rear frame 111B is positioned closer to the vehicle widthdirection central portion at a position farther on the front side asillustrated in FIG. 4 . Accordingly, the left-side rear frame 111A andthe right-side rear frame 111B are each arranged such that the rearframe is positioned on a vehicle-width-direction outer side at aposition farther on the rear side, and the interval between theleft-side rear frame 111A and the right-side rear frame 111B is smallerat a position farther on the front side.

The rear portion of the left-side rear frame 111A is also connected tothe front-rear direction intermediate portion of the left-side rear-sideframe 112A. Accordingly, the left-side rear frame 111A serves as aleft-side connection frame extending from the rear portion of the centerframe 80 to the left-side rear-side frame 112A and connecting the rearportion of the center frame 80 and the left-side rear-side frame 112A.The left-side rear frame 111A also serves as a left-side rear connectionframe connecting the left-side load input portion 110 a and therear-portion cross member 44E. Specifically, a front portion of theleft-side rear frame 111A is fixed to the left-side load input portion110 a, and the rear portion of the left-side rear frame 111A is alsofixed to the rear-portion cross member 44E.

The rear portion of the right-side rear frame 111B is also connected tothe front-rear direction intermediate portion of the right-siderear-side frame 112B. Accordingly, the right-side rear frame 111B servesas a right-side connection frame extending from the rear portion of thecenter frame 80 to the right-side rear-side frame 112B and connectingthe rear portion of the center frame 80 and the right-side rear-sideframe 112B. The right-side rear frame 111B also serves as a right-siderear connection frame connecting the right-side load input portion 110 band the rear-portion cross member 44E. Specifically, a front portion ofthe right-side rear frame 111B is fixed to the right-side load inputportion 110 b, and the rear portion of the right-side rear frame 111B isalso fixed to the rear-portion cross member 44E.

The left-side rear frame 111A is arranged at an upward tilt toward theleft-side load input portion 110 a. Accordingly, an upward load from therear suspension device SP3 is input to the left-side rear frame 111A ina pulling direction, and thus deflection deformation of the left-siderear frame 111A is unlikely to occur as compared to a case in which aload in a compression direction is input, which leads to suppression ofvibration and noise due to load input from the rear suspension deviceSP3. This is same for the right-side rear frame 111B.

The left-side rear frame 111A is arranged on the front side of the leftrear drive shaft S2. The left rear drive shaft S2 is arranged such thatthe left rear drive shaft S2 overlaps with part of the left-side rearframe 111A when viewed in the front-rear direction. Specifically, theheight of a right-left direction intermediate portion of the left reardrive shaft S2 is substantially equal to the height of a part betweenthe front and rear portions of the left-side rear frame 111A.

The right-side rear frame 111B is arranged on the front side of theright rear drive shaft S2. The right rear drive shaft S2 is arrangedsuch that the right rear drive shaft S2 overlaps with part of theright-side rear frame 111B when viewed in the front-rear direction.Specifically, the height of a right-left direction intermediate portionof the right rear drive shaft S2 is substantially equal to the height ofa part between the front and rear portions of the right-side rear frame111B.

As illustrated in FIGS. 3 and 6 , the occupant-space-side floor panel 41includes a front-portion cross member 44A, an intermediate cross member44B, a recessed-portion front-side cross member 44C, a recessed-portionrear-side cross member 44D, and the rear-portion cross member 44E. Thefront-portion cross member 44A, the intermediate cross member 44B, therecessed-portion front-side cross member 44C, the recessed-portionrear-side cross member 44D, and the rear-portion cross member 44E extendin the right-left direction and are fixed to the upper surface of theoccupant-space-side floor panel 41. Thus, the front-portion cross member44A, the intermediate cross member 44B, the recessed-portion front-sidecross member 44C, the recessed-portion rear-side cross member 44D, andthe rear-portion cross member 44E are disposed such that the membersintersect with the center frame 80, which will be described later, in aplan view in the occupant space R1.

The front-portion cross member 44A has an opened sectional structurethat is opened downward, and is disposed at the front portion of theoccupant-space-side floor panel 41. A front portion of the front-portioncross member 44A is also joined to the lower portion of the dash panel50. The intermediate cross member 44B is disposed on the rear side ofthe front-portion cross member 44A and on the front side of the recessedportion 41 a, and a closed cross-section is constituted by theintermediate cross member 44B and the occupant-space-side floor panel41. The rear-portion cross member 44E is disposed at the rear portion ofthe occupant-space-side floor panel 41. The rear-portion cross member44E is also fixed to the connection panel 43.

The recessed-portion front-side cross member 44C is disposed extendingin the right-left direction along the front portion of the recessedportion 41 a on the rear side of the intermediate cross member 44B. Therecessed-portion rear-side cross member 44D is disposed extending in theright-left direction along a rear portion of the recessed portion 41 aon the rear side of the recessed-portion front-side cross member 44C. Aclosed cross-section is constituted by the recessed-portion front-sidecross member 44C and the occupant-space-side floor panel 41, and aclosed cross-section is constituted by the recessed-portion rear-sidecross member 44D and the occupant-space-side floor panel 41. Since therecessed-portion front-side cross member 44C and the recessed-portionrear-side cross member 44D are provided, the part at which the recessedportion 41 a is formed can be reinforced. A front portion of the floorframe 41 c provided inside the recessed portion 41 a is connected to aright-left direction central portion of the recessed-portion front-sidecross member 44C, and a rear portion of the floor frame 41 c isconnected to a right-left direction central portion of therecessed-portion rear-side cross member 44D.

As illustrated in FIG. 8 , the upper-portion structural body 3 includesa pair of right and left left-side seat rails 90 supporting theleft-side front seat FS, and a pair of right and left right-side seatrails 91 supporting the right-side front seat FS. The left-side seatrails 90 are used to adjust the position of the left-side front seat FSin the front-rear direction, are disposed on the left side on theoccupant-space-side floor panel 41, and extend in the front-reardirection. The right-side seat rails 91 are used to adjust the positionof the right-side front seat FS in the front-rear direction, aredisposed on the right side of the occupant-space-side floor panel 41,and extend in the front-rear direction.

The left-side seat rails 90 are positioned higher than the intermediatecross member 44B and the recessed-portion front-side cross member 44Cand attached to the intermediate cross member 44B and therecessed-portion front-side cross member 44C. Specifically, asillustrated in FIG. 9 as well, the left-side seat rails 90 extend fromthe intermediate cross member 44B to the recessed-portion front-sidecross member 44C, front portions of the left-side seat rails 90 areattached to the intermediate cross member 44B, and rear portions of theleft-side seat rails 90 are attached to the recessed-portion front-sidecross member 44C.

Similarly, the right-side seat rails 91 extend from the intermediatecross member 44B to the recessed-portion front-side cross member 44C,front portions of the right-side seat rails 91 are attached to theintermediate cross member 44B, and rear portions of the right-side seatrails 91 are attached to the recessed-portion front-side cross member44C.

As illustrated in FIG. 10 , the intermediate cross member 44B includes afront-portion common bracket 45 to which the front portions of theleft-side seat rails 90 and the front portions of the right-side seatrails 91 are attached in a state in which the seat rails are separatedfrom each other in the right-left direction. Note that the center frame80 is omitted in FIG. 10 . As illustrated in FIG. 11 , the front-portioncommon bracket 45 has a shape that is long in the right-left directionand is fixed to an upper surface of the intermediate cross member 44B. Aright-left direction central portion of the front-portion common bracket45 is positioned at a right-left direction central portion of theintermediate cross member 44B. A central fixation portion 45 a(illustrated only in FIGS. 10 and 11 ) into which a lower portion of asecond connecting member 102 to be described later is inserted isprovided at the right-left direction central portion of thefront-portion common bracket 45. A left-side fixation portion 45 b(illustrated only in FIGS. 4 and 11 ) to which the front portions of theleft-side seat rails 90 are fixed by fastening members such as bolts orscrews is provided on the left side of the central fixation portion 45 aof the front-portion common bracket 45. A right-side fixation portion 45c (illustrated only in FIGS. 4 and 11 ) to which the front portions ofthe right-side seat rails 91 are fixed by fastening members is providedon the right side of the central fixation portion 45 a of thefront-portion common bracket 45. Note that the seat rails are omitted inFIGS. 3 to 5 and 11 .

The recessed-portion front-side cross member 44C includes a rear-portioncommon bracket 46 to which the rear portions of the left-side seat rails90 and the rear portions of the right-side seat rails 91 are attached ina state in which the seat rails are separated from each other in theright-left direction. As illustrated in FIG. 11 , the rear-portioncommon bracket 46 has a shape that is long in the right-left directionand is fixed to an upper surface of the recessed-portion front-sidecross member 44C. A right-left direction central portion of therear-portion common bracket 46 is positioned at the right-left directioncentral portion of the recessed-portion front-side cross member 44C. Acentral fixation portion 46 a (illustrated only in FIGS. 10 and 11 ) inwhich a lower portion of a connecting member to be described later isinserted and fixed is provided at the right-left direction centralportion of the rear-portion common bracket 46. A left-side fixationportion 46 b (illustrated only in FIGS. 4 and 11 ) to which the rearportions of the left-side seat rails 90 are fixed by fastening membersis provided on the left side of the central fixation portion 46 a of therear-portion common bracket 46. A right-side fixation portion 46 c(illustrated only in FIGS. 4 and 11 ) to which the rear portions of theright-side seat rails 91 are fixed by fastening members is provided onthe right side of the central fixation portion 46 a of the rear-portioncommon bracket 46.

As illustrated in, for example, FIG. 8 , the upper-portion structuralbody 3 includes the center frame 80 that is continuous from the dashpanel 50 to the connection panel 43. The center frame 80 is positionedat a right-left direction central portion, and also the front-portioncentral member 16 and the first to third rear-portion central members 17to 19 of the battery unit Y are positioned at the right-left directioncentral portion. Specifically, the disposition positions of thefront-portion central member 16 and the first to third rear-portioncentral members 17 to 19 and the center frame 80 are set to have apositional relation in which the front-portion central member 16 and thefirst to third rear-portion central members 17 to 19 each overlaps withthe center frame 80 in a plan view.

The center frame 80 is disposed to be higher than and away from theoccupant-space-side floor panel 41 at a right-left direction centralportion of the occupant space R1 and extends in the front-reardirection. The distance between a lower surface of the center frame 80and the upper surface of the occupant-space-side floor panel 41 may beset to be, for example, equal to or larger than 10 cm or equal to orlarger than 20 cm at a part separated most. The left-side front seat FSand a rear seat RS are disposed on the left side of the center frame 80,and the right-side front seat FS and a rear seat RS are disposed on theright side of the center frame 80.

Since the center frame 80 is arranged to be higher than and away fromthe occupant-space-side floor panel 41, components and the like can bedisposed in a space between a lower surface of the center frame 80 andthe upper surface of the occupant-space-side floor panel 41.Alternatively, the space between the lower surface of the center frame80 and the upper surface of the occupant-space-side floor panel 41 canbe used as an object housing unit. As illustrated in FIGS. 5 and 6 , thecenter frame 80 according to the present embodiment includes a bendportion 80A that bends in the up-down direction at a front-reardirection intermediate portion. Since the bend portion 80A is providedin the center frame 80, for example, a rear-side part of the centerframe 80 can be positioned lower than a front-side part of the centerframe 80, and thus comfortability of rear-seat passengers can beimproved. Since the front-side part of the center frame 80 can bepositioned higher than the rear-side part of the center frame 80, alarge-sized component or object, a plurality of components, or the likecan be arranged at a lower position than the front-side part of thecenter frame 80. The bend portion 80A is formed at a site on the frontside of a front-rear direction central portion of the center frame 80.The formation position of the bend portion 80A is not limited to theillustrated position but may be, for example, the front-rear directioncentral portion of the center frame 80 or a site on the rear side of thefront-rear direction central portion of the center frame 80.

Specifically, the center frame 80 includes a front-side frame member 81extending in the front-rear direction, a rear-side frame member 82disposed on the vehicle rear side of the front-side frame member 81 andextending toward the rear side, and a connection member 83 connecting arear portion of the front-side frame member 81 and a front portion ofthe rear-side frame member 82. The front-side frame member 81 and therear-side frame member 82 have hollow shapes, in other words, tubularshapes extending in the front-rear direction and may be formed of, forexample, an extruded material. The front-side frame member 81 and therear-side frame member 82 having hollow shapes are lightweight andhigh-stiffness members. When the center frame 80 is used as an airsending means of air-conditioned air to be described later, a rearportion of the rear-side frame member 82 may be blocked to preventleakage of air-conditioned air.

Vertical cross-sections of the front-side frame member 81 and therear-side frame member 82 in the vehicle width direction haverectangular shapes, and thus the front-side frame member 81 and therear-side frame member 82 each include an upper wall portion and a lowerwall portion extending in the right-left direction and right and leftsidewall portions extending in the up-down direction. Note that thecross-sectional shapes of the front-side frame member 81 and therear-side frame member 82 are not limited to rectangular shapes but maybe pentagonal shapes or higher polygonal shapes or may be circularshapes or elliptical shapes.

The dimension of the rear-side frame member 82 in the longitudinaldirection is set to be longer than the dimension of the front-side framemember 81 in the longitudinal direction. Accordingly, a connection partbetween the front-side frame member 81 and the rear-side frame member 82is positioned on the front side of a front-rear direction centralportion of the occupant space R1. Note that the center frame 80 is notlimited to the two-division structure of the front-side frame member 81and the rear-side frame member 82 but may be formed as one member afront portion to a rear portion or may have a three-division structure.

The front-side frame member 81 is tilted at a first tilt angle relativeto a horizontal plane and extends straight. The rear-side frame member82 is tilted at a second tilt angle smaller than the first tilt anglerelative to the horizontal plane and extends straight. Since therear-side frame member 82 is tilted at a tilt angle different from thatof the front-side frame member 81, the bend portion 80A that bendsdownward is formed at the connection part between the front-side framemember 81 and the rear-side frame member 82. In the present embodiment,the rear-side frame member 82 is arranged at a downward tilt toward therear side. Note that the front-side frame member 81 and the rear-sideframe member 82 may have the same tilt angle. In this case, no bendportion 80A is formed.

As illustrated in FIGS. 12 and 13 , inside the rear-side frame member82, a first partition wall portion 82 a for partitioning the inner spaceinto an upper path and a lower path is provided extending in the vehiclewidth direction and the front-rear direction. In addition, inside therear-side frame member 82, a second partition wall portion 82 b forseparating a left path on the vehicle-width-direction left side from aright path on the vehicle-width-direction right side is providedextending in the up-down direction and the front-rear direction. Thefirst partition wall portion 82 a and the second partition wall portion82 b are integrally formed. Four paths, namely, an upper-left path T11,an upper-right path T12, a lower-left path T13, and a lower-right pathT14 are formed inside the rear-side frame member 82 by the firstpartition wall portion 82 a and the second partition wall portion 82 b.The first partition wall portion 82 a and the second partition wallportion 82 b function as ribs provided inside the center frame 80. Notethat the first partition wall portion 82 a and the second partition wallportion 82 b may be provided as necessary, and one or both thereof maybe omitted. Three partition wall portions or more may be provided.

Inside the front-side frame member 81, similarly to the inside of therear-side frame member 82, a first partition wall portion 81 a isprovided extending in the vehicle width direction and the front-reardirection, and an inner space of the front-side frame member 81 isdivided into an upper path and a lower path by the first partition wallportion 81 a. In addition, a second partition wall portion 81 b thatseparates a left path on the vehicle-width-direction left side from aright path on the vehicle-width-direction right side is provided insidethe front-side frame member 81. Similarly to the rear-side frame member82, an upper-left path T11, an upper-right path T12, a lower-left pathT13, and a lower-right path T14 are formed inside the front-side framemember 81 by the first partition wall portion 81 a and the secondpartition wall portion 81 b.

As illustrated in FIGS. 14 to 16 , the connection member 83 has atubular shape connecting the rear portion of the front-side frame member81 and the front portion of the rear-side frame member 82 to allowcommunication therebetween, and the rear portion of the front-side framemember 81 and the front portion of the rear-side frame member 82 areconnected in a state of being inserted in the connection member 83.Specifically, the connection member 83 includes an upper wall portion 83a and a lower wall portion 83 b extending in the right-left directionand a left wall portion 83 c and a right wall portion 83 d extending inthe up-down direction. The upper wall portion 83 a extends from an upperportion of the left wall portion 83 c to an upper portion of the rightwall portion 83 d, and the lower wall portion 83 b extends from a lowerportion of the left wall portion 83 c to a lower portion of the rightwall portion 83 d. The dimension of the lower wall portion 83 b of theconnection member 83 in the front-rear direction is set to be longerthan the dimension of the upper wall portion 83 a in the front-reardirection. The dimensions of the left wall portion 83 c and the rightwall portion 83 d in the front-rear direction are longer at a lowerposition in accordance with the difference between the dimensions of theupper wall portion 83 a and the lower wall portion 83 b in thefront-rear direction.

A first connection wall portion 83 e extending in the right-leftdirection from an up-down direction intermediate portion of the leftwall portion 83 c to an up-down direction intermediate portion of theright wall portion 83 d and a second connection wall portion 83 fextending from a right-left direction intermediate portion of the upperwall portion 83 a to a right-left direction intermediate portion of thelower wall portion 83 b are provided inside the connection member 83.The first connection wall portion 83 e and the second connection wallportion 83 f are integrally formed with the upper wall portion 83 a, thelower wall portion 83 b, the left wall portion 83 c, and the right wallportion 83 d.

A front-side cutout portion 83 g into which the rear portion of thefront-side frame member 81 is inserted is formed on the front side ofthe second connection wall portion 83 f. A rear-side cutout portion 83 hinto which the front portion of the rear-side frame member 82 isinserted is formed on the rear side of the second connection wallportion 83 f. When the front-side frame member 81 and the rear-sideframe member 82 are connected to each other through the connectionmember 83, the upper-left path T11, the upper-right path T12, thelower-left path T13, and the lower-right path T14 of the front-sideframe member 81 communicate with the upper-left path T11, theupper-right path T12, the lower-left path T13, and the lower-right pathT14, respectively, of the rear-side frame member 82.

The bend portion 80A may be provided without the connection member 83.In this case, the bend portion 80A of the center frame 80 can be formedthrough bending fabrication of the center frame 80. For example, thebending fabrication may be simultaneously provided when the center frame80 is fabricated by extrusion, or the bending fabrication may beprovided after the extrusion fabrication.

As illustrated in FIG. 17 , the upper-portion structural body 3 includesan air-conditioning device 120 that generates air-conditioned air to besent to the occupant space R1. The air-conditioning device 120 isdisposed on the front side of a front portion of the front-side framemember 81 and positioned on the front side of the center frame 80. Theair-conditioning device 120 will be described later in detail.

As illustrated in FIG. 20 , the center frame 80 includes a left-sideframe member 84A and a right-side frame member 84B constituting thefront portion of the center frame 80, and accordingly, the front portionof the center frame 80 has a shape bifurcated in the right-leftdirection. The left-side frame member 84A and the right-side framemember 84B are provided at an interval from each other in the right-leftdirection. A rear portion of the left-side frame member 84A is fixed toa left-side surface of a front-rear direction intermediate portion ofthe front-side frame member 81. The left-side frame member 84A is tiltedfrom a fixation part to the front-side frame member 81 toward the frontside in a plan view such that the left-side frame member 84A ispositioned farther on the left side at a position farther on the frontside. A front portion of the left-side frame member 84A is connected toa part of the dash panel 50 higher than and away from theoccupant-space-side floor panel 41. A rear portion of the left-sidefront frame 54A is connected to the front portion of the left-side framemember 84A. Specifically, as illustrated in FIG. 20 , the rear portionof the left-side front frame 54A includes a left-side connection portion54 a. The left-side connection portion 54 a is a member for connectingthe left-side front frame 54A to the front portion of the left-sideframe member 84A and is fixed to the dash panel 50. A front portion ofthe left-side front frame 54A extends to the left-side front-wheelsuspension support member 51A and is fixed to the left-side front-wheelsuspension support member 51A.

A rear portion of the right-side frame member 84B is fixed to aright-side surface of the front-rear direction intermediate portion ofthe front-side frame member 81. The right-side frame member 84B istilted from a fixation part to the front-side frame member 81 toward thefront side in a plan view such that the right-side frame member 84B ispositioned farther on the right side at a position farther on the frontside. A front portion of the right-side frame member 84B is connected tothe part of the dash panel 50 higher than and away from theoccupant-space-side floor panel 41. A rear portion of the right-sidefront frame 54B (illustrated in FIG. 4 ) is connected to the frontportion of the right-side frame member 84B. Specifically, the rearportion of the right-side front frame 54B includes a right-sideconnection portion 54 b as illustrated in FIG. 20 . The right-sideconnection portion 54 b is a member for connecting the right-side frontframe 54B to the front portion of the right-side frame member 84B and isfixed to the dash panel 50. A front portion of the right-side frontframe 54B extends to the right-side front-wheel suspension supportmember 51B and is fixed to the right-side front-wheel suspension supportmember 51B.

The upper-portion structural body 3 includes a plurality of connectingmembers 101 to 103. The connecting members 101 to 103 are members forconnecting the center frame 80 to the occupant-space-side floor panel41, each member extending upward from the occupant-space-side floorpanel 41 and having an upper portion fixed to the center frame 80. Theconnecting members 101 to 103 include the first connecting member 101,the second connecting member 102, and the third connecting member 103and are each formed of, for example, an extruded material. The number ofconnecting members 101 to 103 is not limited to plurality but may be twoor may be one. The first connecting member may be the connecting member102, and the second connecting member may be the connecting member 103.Alternatively, the first cross member may be the intermediate crossmember 44B, and the second cross member may be the recessed-portionfront-side cross member 44C.

Among the first to third connecting members 101 to 103, the firstconnecting member 101 is disposed farthest on the front side in theoccupant space R1, and the first connecting member 101 is separated onthe rear side from the dash panel 50. A lower portion of the firstconnecting member 101 is fixed to a site separated on the rear side fromthe dash panel 50 on the occupant-space-side floor panel 41, and anupper portion of the first connecting member 101 is fixed to a siteseparated on the rear side from the dash panel 50 on the center frame80. Accordingly, a closed cross-section structure is constituted in aside view by the center frame 80, the first connecting member 101, theoccupant-space-side floor panel 41, and the dash panel 50. Specifically,the center frame 80, the first connecting member 101, theoccupant-space-side floor panel 41, and the dash panel 50 are connectedto form an annular structure.

As illustrated in, for example, FIG. 3 , the second connecting member102 is separately disposed on the rear side of the first connectingmember 101. The lower portion of the first connecting member 101 and alower portion of the second connecting member 102 are fixed to sitesseparated from each other in the front-rear direction on theoccupant-space-side floor panel 41. The upper portion of the firstconnecting member 101 and an upper portion of the second connectingmember 102 are fixed to sites separated from each other in thefront-rear direction of the center frame 80. Accordingly, a closedcross-section structure is constituted in a side view by the centerframe 80, the first connecting member 101, the occupant-space-side floorpanel 41, and the second connecting member 102. The third connectingmember 103 is separately disposed on the rear side of the secondconnecting member 102.

As illustrated in FIG. 20 , the first connecting member 101 includes aleft-side member (left-side connecting member) 101A and a right-sidemember (right-side connecting member) 101B. Lower portions of theleft-side member 101A and the right-side member 101B are fixed to thefront-portion cross member 44A but may be directly fixed to a body partof the occupant-space-side floor panel 41. The left-side member 101Aextends at a tilt in a front view such that the left-side member 101A ispositioned farther on the left side at a position farther on the upperside from the front-portion cross member 44A. An upper portion of theleft-side member 101A is fixed to the front portion of the left-sideframe member 84A of the center frame 80. The upper portion of theleft-side member 101A may be fixed to the left-side connection portion54 a. In this case, the left-side member 101A connects the left-sideconnection portion 54 a and the occupant-space-side floor panel 41.

The right-side member 101B extends at a tilt in a front view such thatthe right-side member 101B is positioned farther on the right side at aposition farther on the upper side from the front-portion cross member44A. An upper portion of the right-side member 101B is fixed to thefront portion of the right-side frame member 84B of the center frame 80.The upper portion of the right-side member 101B may be fixed to theright-side connection portion 54 b. In this case, the right-side member101B connects the right-side connection portion 54 b and theoccupant-space-side floor panel 41. Since the front portion of theleft-side frame member 84A and the front portion of the right-side framemember 84B are separated from each other in the right-left direction,most parts of the left-side member 101A and the right-side member 101Bexcept for the lower portions thereof are separated from each other inthe right-left direction, and accordingly, the interval between theleft-side member 101A and the right-side member 101B in the right-leftdirection is larger at a position farther on the upper side.

The first connecting member 101 may connect the rear portion of theleft-side front frame 54A to the occupant-space-side floor panel 41. Inthis case, the upper portion of the left-side member 101A of the firstconnecting member 101 is fixed to the rear portion of the left-sidefront frame 54A, and the lower portion of the left-side member 101A isfixed to the occupant-space-side floor panel 41. The first connectingmember 101 may connect the rear portion of the right-side front frame54B to the occupant-space-side floor panel 41. In this case, the upperportion of the right-side member 101B of the first connecting member 101is fixed to the rear portion of the right-side front frame 54B, and thelower portion of the right-side member 101B is fixed to theoccupant-space-side floor panel 41.

The dimension of the second connecting member 102 in the right-leftdirection is set to be longer than the dimension thereof in thefront-rear direction and equal to or smaller than the dimension of thecenter frame 80 in the right-left direction. Accordingly, right and leftsides of the second connecting member 102 do not protrude from thecenter frame 80 in the right-left direction. A cross-section of thesecond connecting member 102 is set to be larger than a cross-section ofthe left-side member 101A or the right-side member 101B.

The lower portion of the second connecting member 102 is fixed betweenthe left-side seat rails 90 and the right-side seat rails 91 at thefront-portion common bracket 45 included in the intermediate crossmember 44B. Specifically, the lower portion of the second connectingmember 102 is fixed in a state of being inserted in the central fixationportion 45 a provided at the right-left direction central portion of thefront-portion common bracket 45. Thus, the common bracket 45 to whichthe left-side seat rails 90 and the right-side seat rails 91 areattached becomes a member having a high strength, and in addition, thedimension thereof in the vehicle width direction is long to some extent,and accordingly, a large range of fixation to a body part of the crossmember 44B is obtained and fixation strength increases. When the lowerportion of the second connecting member 102 is fixed to the commonbracket 45 having a high strength and a high fixation strength in thismanner, the strength of connection of the center frame 80 by the secondconnecting member 102 is further increased. Note that the lower portionof the second connecting member 102 may be directly fixed to the bodypart of the occupant-space-side floor panel 41 or may be directly fixedto the intermediate cross member 44B.

The upper portion of the second connecting member 102 is fixed to thebend portion 80A of the center frame 80. Specifically, the upper portionof the second connecting member 102 is fixed to the lower wall portion83 b of the connection member 83. Accordingly, the second connectingmember 102 extends from the bend portion 80A of the center frame 80toward the occupant-space-side floor panel 41. Since the dimension ofthe lower wall portion 83 b of the connection member 83 in thefront-rear direction is longer than the dimension of the upper wallportion 83 a in the front-rear direction, a large area of joint to thesecond connecting member 102 is obtained. When the connection member 83is omitted, the upper portion of the second connecting member 102 may bedirectly fixed to the center frame 80.

Similarly to the second connecting member 102, the third connectingmember 103 has a cross-section that is long in the right-left direction.A lower portion of the third connecting member 103 is fixed to therecessed-portion front-side cross member 44C. An upper portion of thethird connecting member 103 is fixed to the lower wall portion of therear-side frame member 82 of the center frame 80. As illustrated in FIG.8 as well, the third connecting member 103 is also fixed to the frontportion of the floor frame 41 c.

As illustrated in FIG. 4 , the rear portion of the center frame 80 isconnected to the connection panel 43 and the rear-portion cross member44E. Specifically, a rear-portion connecting member 104 is fixed to therear portion of the center frame 80, and a right-left direction centralportion of the rear-portion cross member 44E is fixed to a lower portionof the rear-portion connecting member 104. The rear portion of thecenter frame 80 and the rear-portion cross member 44E are connected toeach other through the rear-portion connecting member 104.

The rear side of the rear-portion connecting member 104 is fixed to theconnection panel 43. Accordingly, the rear portion of the center frame80 is also connected to the connection panel 43 through the rear-portionconnecting member 104. The lower portion of the rear-portion connectingmember 104 is also fixed to the rear portion of the occupant-space-sidefloor panel 41. In other words, the dash panel 50 and the connectionpanel 43 are connected to each other through the center frame 80. Inthis case, since the center frame 80 is positioned higher than and awayfrom the occupant-space-side floor panel 41, the occupant-space-sidefloor panel 41, the dash panel 50, the connection panel 43, and thecenter frame 80 integrate and constitute a closed cross-sectionstructure in a side view. Accordingly, the distortion stiffness of thevehicle body is sufficiently improved although the occupant-space-sidefloor panel 41 of a floor tunnel-less structure is included.

In addition, the front portion of the left-side rear frame 111A and thefront portion of the right-side rear frame 111B are fixed to the lowerportion of the rear-portion connecting member 104. Thus, the rearportion of the center frame 80 and the left-side rear-wheel suspensionsupport member 110A are connected to each other through the left-siderear frame 111A, and the rear portion of the center frame 80 and theright-side rear-wheel suspension support member 110B are connected toeach other through the right-side rear frame 111B. Accordingly, thestiffness of the rear-wheel suspension support members 110A and 110B canbe increased, which improves maneuvering stability of the vehicle. Inaddition, the stiffness of the vehicle rear side including theconnection panel 43 and the vicinity thereof is increased as well.

FIGS. 18 and 19 are diagrams illustrating a case in which the tilt angleof the center frame 80 is large. In this example, the rear portion ofthe center frame 80 is connected to the rear portion of the floor frame41 c. The center frame 80 has a straight shape including no bendportion, but a bend portion may be formed. The rear portion of thecenter frame 80 is arranged at a lower position than a vehicle frontportion of the seat cushion of each rear seat RS. Accordingly, the rearportion of the center frame 80 is unlikely to interfere with passengerson the rear seats RS, and thus degradation of comfort of the rear-seatpassengers is avoided. The rear portion of the center frame 80 is alsofixed to the occupant-space-side floor panel 41.

In the example illustrated in FIG. 19 , the rear portion of the centerframe 80 is also connected to a front portion of the rear reinforcementmember 47. In this example, since the recessed-portion rear-side crossmember 44D is provided at the rear portion of the recessed portion 41 a,the recessed portion 41 a and the vicinity thereof are reinforced by therecessed-portion rear-side cross member 44D. The recessed portion 41 aand the vicinity thereof are also reinforced by the floor frame 41 c. Inaddition, since the center frame 80 higher than and away from theoccupant-space-side floor panel 41 is connected to the floor frame 41 c,the distortion stiffness of the vehicle body is sufficiently improved.

As illustrated in FIG. 5 , the traveling motor M included in therear-side powertrain PT is supported to each rear support frame 30through the non-illustrated mounting member or the like and is disposedon the vehicle rear side of the rear portion of the center frame 80. Theheight of the rear-side traveling motor M can optionally set inaccordance with the height of attachment to each rear support frame 30.In the present embodiment, the height of the rear-side traveling motor Mis set such that the height of at least part of the range from an upperportion of the rear-side traveling motor M to a lower portion thereof isequal to the height of the rear portion of the center frame 80. Inaddition, the height of a rotation center of the rear-side travelingmotor M, in other words, the height of an up-down direction centralportion of the traveling motor M is set to be lower than that of therear portion of the center frame 80. Since the rear-side powertrain PTis arranged in this manner, for example, a load toward the vehicle frontside is applied to the rear portion of the center frame 80 when animpact load applied from the vehicle rear side is input to the travelingmotor M and the traveling motor M is about to move toward the vehiclefront side. In this case, since the rear portion of the center frame 80is connected to the rear-portion cross member 44E, the connection panel43, and the like and integrated with the occupant-space-side floor panel41, the movement of the traveling motor M toward the front side isprevented by the center frame 80. The movement of the traveling motor Mtoward the front side is also prevented by the occupant-space-side floorpanel 41 and the rear-portion cross member 44E.

Subsequently, a layout of the front-side powertrain PT will be describedbelow based on FIG. 17 . The front-side powertrain PT is supported toeach front support frame 20 through the non-illustrated mounting memberor the like. The height of the front-side traveling motor M can beoptionally set in accordance with the height of attachment to each frontsupport frame 20. The front-side powertrain PT is arranged on the frontside of the first connecting member 101. At least part of theair-conditioning device 120 is arranged between the first connectingmember 101 and the powertrain PT.

The air-conditioning device 120 includes a cooler (heat exchanger) 121through which air-conditioned air passes, and an air conditioning casing122 in which the cooler 121 is housed. The cooler 121 is a cooling heatexchanger including, for example, an evaporator for coolingair-conditioned air. The cooler 121 is not limited thereto, but aheating heat exchanger including a heater core or condenser that heatsair-conditioned air may be used in place of the cooler 121, and a coolermay be disposed at another part. The cooler 121 of the presentembodiment is disposed on the front side of the dash panel 50. Acompressor that compresses a coolant, an expansion valve thatdepressurizes the coolant, and the like constitute part of theair-conditioning device 120.

An up-down direction central portion of the cooler 121 is arranged at ahigher position than a rotation center of the front-side traveling motorM. Specifically, for example, when the automobile 1 collides on thefront side and an impact load toward the rear side is applied to thepowertrain PT, the powertrain PT starts retracting depending on themagnitude of the impact load. Since the front-side powertrain PT isarranged as described above, the center frame 80 extending in thefront-rear direction is arranged on the rear side of the powertrain PTin a state of being connected to the occupant-space-side floor panel 41through the connecting members 101 to 103. Accordingly, the retractionof the powertrain PT is suppressed by the center frame 80 and theconnecting members 101 to 103. Since the occupant-space-side floor panel41 is also positioned on the rear side of the powertrain PT, theretraction of the powertrain PT is suppressed by the occupant-space-sidefloor panel 41 as well in some cases.

Subsequently, a specific exemplary configuration of the air-conditioningdevice 120 will be described below. In addition to the above-describedcooler 121, a heater, an air mix damper 122 a for generatingair-conditioned air at a desired temperature by changing the mixed ratioof cool air having passed through the cooler 121 and warm air havingpassed through the heater, and a vent direction switching damper 122 bfor distributing the generated air-conditioned air at the desiredtemperature to each component of a vehicle cabin are housed inside theair conditioning casing 122 of the air-conditioning device 120. Throughoperation of the vent direction switching dampers 122 b, theair-conditioned air can be supplied to the inner surface of a frontwindow glass FG (illustrated in FIG. 1 ), supplied to the upper body ofa passenger, and supplied to the vicinity of the feet of a passenger.The operation of the vent direction switching damper 122 b has beenconventionally well known.

A front-side part of the air conditioning casing 122 is a part in whichthe cooler 121 and the air mix damper 122 a are housed, and is arrangedon the front side of the dash panel 50. A rear-side part of the airconditioning casing 122 is a part in which the vent direction switchingdamper 122 b is housed, and is arranged in the occupant space R1 throughthe dash panel 50. Accordingly, the cooler 121 and the air mix damper122 a are positioned closer to the powertrain PT than the vent directionswitching damper 122 b. Note that the front-side part of the airconditioning casing 122 may be arranged on the rear side of the dashpanel 50.

The rear-side part of the air conditioning casing 122 includes a ventportion 122 c having a duct shape through which the air-conditioned airgenerated inside the air conditioning casing 122 is vented out. The airconditioning casing 122 also includes an air introducing duct 122 d thatprovides communication between the vent portion 122 c and the inside ofthe center frame 80 and through which the air-conditioned air vented outof the vent portion 122 c is introduced to the inside of the centerframe 80. The air introducing duct 122 d is arranged at a higherposition than a control device 130 to be described later and extends inthe front-rear direction. A front portion of the air introducing duct122 d is connected to the vent portion 122 c, and a rear portion of theair introducing duct 122 d is connected to the front portion of thefront-side frame member 81 of the center frame 80. Accordingly, theair-conditioned air generated by the air-conditioning device 120 isintroduced to the inside of the center frame 80 through the airintroducing duct 122 d. The air introducing duct 122 d may be a memberthat constitutes part of the center frame 80.

Since the center frame 80 extends in the front-rear direction, theair-conditioned air can be guided to a desired place in the front-reardirection in the occupant space R1. In this case, since the airintroducing duct 122 d is arranged at a higher position than the controldevice 130 and has a predetermined width in the right-left direction,direct sunlight is interrupted by the air introducing duct 122 d as welland further unlikely to reach the control device 130. Moreover, sincethe center frame 80 is used as an air conditioning duct, an airconditioning duct does not need to be redundantly provided and theoccupant space R1 can be enlarged as compared to a case in which an airconditioning duct is redundantly provided.

As illustrated in FIG. 20 , upper-side air sending portions 80 b forsending the air-conditioned air in the upper-left path T11 and theupper-right path T12 upward is provided at parts separated on the rearside from the air introducing duct 122 d at an upper wall portion of thecenter frame 80. The upper-side air sending portions 80 b are positionedon the rear side of backrest portions of the front seats FS at the upperwall portion of the center frame 80 and provided on the right and leftsides, respectively. The left-side upper-side air sending portion(left-side air sending portion) 80 b has a tubular shape thatcommunicates with the inside of the upper-left path T11, and theright-side upper-side air sending portion (right-side air sendingportion) 80 b has a tubular shape that communicates with the inside ofthe upper-right path T12. Downstream ends of the upper-side air sendingportions 80 b are opened upward to face passengers sitting on the rearseats RS.

As illustrated in FIG. 5 , lower-side air sending portions 80 c forsending the air-conditioned air in the lower-left path T13 and thelower-right path T14 downward are provided at parts separated on therear side from the air introducing duct 122 d at a lower wall portion ofthe center frame 80. The lower-side air sending portions 80 c arepositioned on the rear side of seat cushion portions of the front seatsFS and provided on the right and left sides, respectively, of the lowerwall portion of the center frame 80. The left-side lower-side airsending portion 80 c has a tubular shape that communicates with theinside of the lower-left path T13, and the right-side lower-side airsending portion 80 c has a tubular shape that communicates with theinside of the lower-right path T14. Each lower-side air sending portion80 c is constituted by a rear under-feet duct extending downward towardthe recessed portion 41 a, and extending downward from the center frame80 and then bending toward a vehicle-width-direction outer side. Therear under-feet duct may be referred to as a rear heat duct.

Since the center frame 80 has a cross-section that is large enough toimprove the distortion stiffness of the vehicle body, air sending noisecan be maintained low when the amount of the air-conditioned aircirculating inside the center frame 80 is increased. In particular,since the center frame 80 extends in a substantially straight shape, apath inside the center frame 80 has a substantially straight shape aswell, and air sending noise can be maintained low for this reason aswell. When the center frame 80 includes no heat insulation material northe like, heat of the air-conditioned air circulating inside the centerframe 80 is transferred to a wall portion of the center frame 80 andradiated from the outer surface of the wall portion to the occupantspace R1. Accordingly, it is possible to perform desirable airconditioning by using radiation heat. Note that the center frame 80 mayinclude a heat insulation material.

Layout of Control Device

The vehicle-body structure A includes the control device 130(illustrated in, for example, FIGS. 9, 17, and 23 ) that controlscontrol target units mounted on the automobile 1. Examples of thecontrol target units include the powertrains PT, a brake device, anelectric control suspension device, a lighting device, a navigationdevice, a head-up display device, an audio device, an in-vehiclemonitor, and a television. The control device 130 that controls thesecontrol target units includes a high-performance CPU, a memory, and thelike, and thus has an increased size and is weak against high heat andalso weak against impact. For example, a water jacket through whichcooling water circulates is provided as a heat generation measure in thecontrol device 130. An in-vehicle entertainment function (moving imageplayback function or music playback function) or the like is mounted insome cases, and in such a case as well, the size of the control device130 increases.

The control device 130 of the present embodiment is arranged at a lowerposition than the front portion of the center frame 80 in the occupantspace R1. As described above, since the height of the front portion ofthe center frame 80 is higher than the rear portion of the center frame80, the control device 130 having a large size can be arranged. Asillustrated with a virtual line in FIG. 17 , an instrument panel IP towhich meters and gauges are attached is arranged at a higher positionthan the front portion of the center frame 80. The instrument panel IPextends in the right-left direction from the left side of the occupantspace R1 to the right side thereof. A front portion of the instrumentpanel IP reaches a lower portion of the front window glass FG(illustrated in FIG. 1 ).

The left-side member 101A and the right-side member 101B constitutingthe first connecting member 101 are arranged on the front side of thecontrol device 130. The second connecting member 102 is arranged on therear side of the control device 130. Accordingly, the control device 130is arranged between the first connecting member 101 and the secondconnecting member 102, and gaps are provided between the firstconnecting member 101 and the control device 130 and between the secondconnecting member 102 and the control device 130, respectively.

Since the control device 130 is arranged at a lower position than thecenter frame 80 in the occupant space R1, for example, direct sunlightfrom the outside is interrupted by the center frame 80 and unlikely toreach the control device 130. Thus, the control device 130 can bearranged at a thermally advantageous place. Moreover, since theinstrument panel IP is arranged at a higher position than the controldevice 130, direct sunlight is interrupted by the instrument panel IP aswell and further unlikely to reach the control device 130. Since thecontrol device 130 is covered by the instrument panel IP, the controldevice 130 is unlikely to be viewed from the outside, which ispreferable in terms of security.

The air introducing duct 122 d is disposed at a higher position than thecontrol device 130. Heat of the air-conditioned air is transferred to awall portion of the air introducing duct 122 d and radiated as radiationheat from the outer surface of the wall portion toward the controldevice 130. In this case, since the air-conditioned air having atemperature adjusted so that the occupant space R1 becomes comfortableflows inside the air introducing duct 122 d, the radiation heat from theair introducing duct 122 d acts on to suppress temperature increase ofthe control device 130. Moreover, direct sunlight can be interrupted bythe air introducing duct 122 d.

For example, when a case in which an impact load is applied from thefront side is assumed, at least part of the impact load is absorbed bythe center frame 80 and deformation of the vehicle body in the vicinityof the center frame 80 is suppressed since the center frame 80 extendsin the front-rear direction. Accordingly, the control device 130arranged at a lower position than the center frame 80 is protectedagainst the impact load from the front side. This is same for an impactload from the rear side. In particular, at least two places of thecenter frame 80 can be solidly connected to the occupant-space-sidefloor panel 41 through the left-side member 101A and the right-sidemember 101B, and thus protection performance of the control device 130can be increased.

When a case in which an impact load is applied from a side of thevehicle is assumed, the impact load from a side is unlikely to bedirectly conveyed to the control device 130 since the control device 130is arranged corresponding to the vehicle width direction centralportion, and thus the control device 130 is protected against the impactload from a side as well. In addition, since the control device 130 isarranged between the first connecting member 101 and the secondconnecting member 102, an impact load in the front-rear direction isunlikely to be applied to the control device 130 and the protectionperformance further improves.

Cooling Path

Subsequently, a cooling path will be described below. FIG. 21 is adiagram illustrating a schematic structure of a cooling path provided inthe automobile 1. The cooler 121 can be constituted by, for example, acooling heat exchanger of the air-conditioning device 120, but is notlimited thereto and may be a dedicated cooler provided separately fromthe air-conditioning device 120. A path of cooling water as a heatexchange medium is formed in the cooler 121, and the cooling watercirculating through the path is cooled through heat exchange with alow-temperature coolant inside the cooler 121. The vehicle-bodystructure A includes a supply pipe 131 for supplying the cooling watercooled by the cooler 121 to the water jacket included in the controldevice 130, and a discharge pipe 132 for discharging the cooling watersupplied to the control device 130. The supply pipe 131 is provided witha pump P for transferring the cooling water to the control device 130.The cooling water discharged from the discharge pipe 132 is cooledthrough the cooler 121 and then taken into the pump P. The controldevice 130 is cooled as the cooling water is circulated in this manner.The cooling water having cooled the control device 130 is used to coolthe batteries FB and RB, used to cool the traveling motor M, and thenreturned to the cooler 121. Note that a coolant may be used in place ofthe cooling water.

As illustrated in FIG. 17 , the cooler 121 is disposed on the rear sideof the front-side powertrain PT and positioned close to the dash panel50. Accordingly, the cooler 121 is positioned closer to the controldevice 130 than the front-side powertrain PT. Thus, the length of thesupply pipe 131 can be short and a pipe path is simple, which leads toreduction of a pressure loss when the cooling water is supplied to thecontrol device 130 and also leads to reduction of a cold loss betweenthe cooler 121 and the control device 130, and accordingly, the controldevice 130 can be efficiently cooled.

As illustrated in FIG. 22 , the supply pipe 131 and the discharge pipe132 extend through the dash panel 50 and are disposed between theleft-side member 101A and the right-side member 101B. Since the supplypipe 131 and the discharge pipe 132 are disposed between the left-sidemember 101A and the right-side member 101B, the supply pipe 131 and thedischarge pipe 132 are unlikely to be hit by the feet of a passenger orthe like, and damage on the supply pipe 131 and the discharge pipe 132is suppressed. The supply pipe 131 and the discharge pipe 132 extend inthe front-rear direction below the air-conditioning device 120.

Working Effects of Embodiments

As described above, according to the present embodiment, since thefront-portion cross member 44A, the intermediate cross member 44B, andthe like are provided in the occupant space R1, a vehicle-bodyreinforcement effect by the cross members 44A and 44B is obtained.Moreover, since the center frame 80 higher than and away from theoccupant-space-side floor panel 41 is connected to the front-portioncross member 44A and the intermediate cross member 44B through theconnecting members 101 and 102, the distortion stiffness of the vehiclebody can be sufficiently improved although the occupant-space-side floorpanel 41 has a floor tunnel-less structure.

In addition, since the connecting members 101 and 102 are fixed to crossmembers 44A and 44B, the fixation strength of the connecting members 101and 102 can be increased. Accordingly, inclination of the connectingmembers 101 and 102 in the front-rear direction is suppressed when animpact load from the front side is applied, and thus a vehicle-cabindeformation suppression effect by the center frame 80 can besufficiently obtained.

Furthermore, since the center frame 80 can be connected to the crossmembers 44A and 44B disposed at an interval from each other in thefront-rear direction, the connection strength of the center frame 80 canbe further increased.

The present disclosure is not limited to only the above-describedembodiments, which are merely exemplary. It will be appreciated by thoseskilled in the art that the disclosed systems and/or methods can beembodied in other specific forms without departing from the spirit ofthe disclosure or essential characteristics thereof. The presentlydisclosed embodiments are therefore considered to be illustrative andnot restrictive. The disclosure is not exhaustive and should not beinterpreted as limiting the claimed invention to the specific disclosedembodiments. In view of the present disclosure, one of skill in the artwill understand that modifications and variations are possible in lightof the above teachings or may be acquired from practicing of thedisclosure.

Reference to an element in the singular is not intended to mean “one andonly one” unless explicitly so stated, but rather “one or more.”Moreover, where a phrase similar to “at least one of A, B, or C” is usedin the claims, it is intended that the phrase be interpreted to meanthat A alone may be present in an embodiment, B alone may be present inan embodiment, C alone may be present in an embodiment, or that anycombination of the elements A, B and C may be present in a singleembodiment; for example, A and B, A and C, B and C, or A and B and C.

No claim element herein is to be construed under the provisions of 35U.S.C. 112(f) unless the element is expressly recited using the phrase“means for.” As used herein, the terms “comprises,” “comprising,” or anyother variation thereof, are intended to cover a non-exclusiveinclusion, such that a process, method, article, or apparatus thatcomprises a list of elements does not include only those elements butmay include other elements not expressly listed or inherent to suchprocess, method, article, or apparatus.

The scope of the invention is indicated by the appended claims, ratherthan the foregoing description.

INDUSTRIAL APPLICABILITY

As described above, the present disclosure is applicable as, forexample, a vehicle-body structure of an electric vehicle.

REFERENCE SIGNS LIST

-   1 automobile-   41 occupant-space-side floor panel-   43 connection panel-   44A front-portion cross member-   44B intermediate cross member-   50 dash panel-   80 center frame-   101 first connecting member-   102 second connecting member-   A vehicle-body structure-   R1 occupant space-   R3 trunk space

1. A vehicle-body structure provided in an automobile, the vehicle-bodystructure comprising: a floor panel constituting a floor of an occupantspace including a seat on which a passenger sits; a center framedisposed to be higher than and away from the floor panel at avehicle-width-direction central portion of the occupant space andextending in a vehicle front-rear direction; a cross structure extendingin a vehicle width direction and intersecting the center frame in a planview in the occupant space; and a connecting structure extending upwardfrom the cross structure, having an upper portion fixed to the centerframe, and connecting the center frame to the cross structure.
 2. Thevehicle-body structure according to claim 1, wherein the cross structurehas an opened sectional structure that is opened downward and is fixedto an upper surface of the floor panel, and a closed cross-section isconstituted by the cross structure and the floor panel.
 3. Thevehicle-body structure according to claim 2, wherein the connectingstructure includes a first connecting structure and a second connectingstructure separately disposed on a vehicle rear side from the firstconnecting structure, the cross structure includes a first crossstructure and a second cross structure separately disposed on thevehicle rear side from the first cross structure, a lower portion of thefirst connecting structure is fixed to the first cross structure, and alower portion of the second connecting structure is fixed to the secondcross structure.
 4. The vehicle-body structure according to claim 3,further comprising a seat rail supporting the seat, wherein the seatrail is attached to at least one of the first cross structure and thesecond cross structure.
 5. The vehicle-body structure according to claim4, wherein the seat rail extends from the first cross structure to thesecond cross structure, a front portion of the seat rail is attached tothe first cross structure, and a rear portion of the seat rail isattached to the second cross structure.
 6. The vehicle-body structureaccording to claim 5, wherein the seat rail includes a left-side seatrail supporting a left-side seat and a right-side seat rail supporting aright-side seat, the cross structure includes a common bracket to whichthe left-side seat rail and the right-side seat rail are attached in astate in which the left-side seat rail and the right-side seat rail areseparated from each other in the vehicle width direction, and a lowerportion of the connecting structure is fixed to the common bracketbetween the left-side seat rail and the right-side seat rail.
 7. Thevehicle-body structure according to claim 1, wherein the connectingstructure includes a first connecting structure and a second connectingstructure separately disposed on a vehicle rear side from the firstconnecting structure, the cross structure includes a first crossstructure and a second cross structure separately disposed on thevehicle rear side from the first cross structure, a lower portion of thefirst connecting structure is fixed to the first cross structure, and alower portion of the second connecting structure is fixed to the secondcross structure.
 8. The vehicle-body structure according to claim 4,wherein the seat rail includes a left-side seat rail supporting aleft-side seat and a right-side seat rail supporting a right-side seat,the cross structure includes a common bracket to which the left-sideseat rail and the right-side seat rail are attached in a state in whichthe left-side seat rail and the right-side seat rail are separated fromeach other in the vehicle width direction, and a lower portion of theconnecting structure is fixed to the common bracket between theleft-side seat rail and the right-side seat rail.